…ache#9234)

This reverts commit 721f373.

# Which issue does this PR close?

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- Discussed in apache#9184
- Closes apache#9184
 
# Rationale for this change

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As discussed in Discussed in
apache#9184, rather than sealing the
`Array` trait, it's going to potentially be marked `unsafe` so that
projects have time to find alternatives for their use-cases that are now
satisfied by a custom `Array` implementation.


# What changes are included in this PR?

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Clean revert of apache#9092

# Are these changes tested?

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Not applicable here

# Are there any user-facing changes?

Yes, users can no implement the `Array` trait in their codebases again.

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